1. Technical Field
This application relates to solid state memory and, in particular, to partial bad blocks in the solid state memory.
2. Related Art
As a die of solid state memory is subjected to stresses and screen, various blocks of the solid state memory may be marked as bad blocks because of failures. Such bad blocks may be called factory marked bad blocks. In order to meet capacity and performance requirements, a limited number of blocks may be factory marked bad blocks in order to pass quality tests.
During runtime, if a write error, such as a program failure, is reported by the solid state memory when writing to a block, the block may be retired and added to a bad block list. The solid state memory may have individually erasable segments, such as pages or blocks. Each of the erasable segments may be put through a limited number of erase cycles before becoming unreliable and being marked a bad block. The bad block may no longer be used to store data.